Armaflex Class O Pipe Insulation 15mm x 19mm

Armaflex Class O Pipe Insulation 15mm x 19mm is plain, unslit Armaflex tube with a 15mm bore and a thick 19mm wall, sold in 2m lengths. This is standard Class O tube, not the self seal type, so it suits new pipework you can sleeve before the joints are made.

What it’s used for

The 19mm wall is the heavy option for 15mm copper. It earns its keep on cold mains in roof spaces and outbuildings, pipework on outside walls, and chilled or air conditioning lines where condensation would otherwise drip on ceilings. Armacell describe the material as flexible, closed cell nitrile rubber, so it carries its own vapour barrier and doesn’t shed fibres or dust. Fire performance is Class O, as the name says.

Plain tube or self seal?

Plain tube is slid on along the pipe, which gives a neat, unbroken finish on a new run. On existing pipework you can slit it yourself with a sharp knife and close the seam with Armaflex adhesive, or pick a self seal tube if you would rather skip that job.

• Bore: 15mm
• Wall: 19mm
• Length: 2m, collected from the counter

Fitting tips

Thread the lengths onto the pipe before you solder or press the last joints, and keep the foam well back from any flame. Where the tube meets a fitting, cut it square and glue the ends together. A thick wall like this is less flexible, so mitre the corners rather than forcing it round. See our full pipe insulation range for other sizes.

Lagging from our Glasgow counter

Order online or drop by the Plumb Parts trade counter at 555 South Street, Glasgow G14 0QX. Open Mon-Fri 8am-5pm, Sat-Sun 8am-1pm.

Specification

• Brand: Armaflex
• Range: Class O pipe insulation
• Material: Flexible closed cell elastomeric (nitrile rubber) foam
• Sizes: 15mm bore, 19mm wall, 2m lengths
• Standard or approval: Class O fire performance, as named
• Suitable for: Insulating 15mm pipe

Common Questions

What does Class O mean on pipe insulation?

Class O is a UK fire performance rating for surfaces, taken from BS 476 tests for flame spread and fire propagation. Building specifications for offices, schools and flats often ask for it.

How many lengths of 15mm x 19mm do I need for a 10m run?

Five 2m lengths cover 10m of straight pipe. Add one more for bends and offcuts round valves.

Is 19mm too thick for a 15mm pipe in a loft?

No, 19mm is the heavier choice for cold loft and outbuilding pipes where frost is a risk. It is bulkier, so check there is room between the pipe and the joists.